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<H1 class="no-header">menu_driver 3x 2024-03-16 ncurses 6.5 Library calls</H1>
<PRE>
<STRONG><A HREF="menu_driver.3x.html">menu_driver(3x)</A></STRONG>                  Library calls                 <STRONG><A HREF="menu_driver.3x.html">menu_driver(3x)</A></STRONG>




</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
       <STRONG>menu_driver</STRONG> - command-processing loop of the menu system


</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
       <STRONG>#include</STRONG> <STRONG>&lt;menu.h&gt;</STRONG>

       <STRONG>int</STRONG> <STRONG>menu_driver(MENU</STRONG> <STRONG>*</STRONG><EM>menu</EM><STRONG>,</STRONG> <STRONG>int</STRONG> <EM>c</EM><STRONG>);</STRONG>


</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
       Once a menu has been posted (displayed), you should funnel input events
       to it through <STRONG>menu_driver</STRONG>.  This routine has three major input cases:

       <STRONG>o</STRONG>   The input is a form navigation request.  Navigation  request  codes
           are constants defined in <STRONG>&lt;form.h&gt;</STRONG>, which are distinct from the key-
           and character codes returned by <STRONG><A HREF="curs_getch.3x.html">wgetch(3x)</A></STRONG>.

       <STRONG>o</STRONG>   The input is a printable character.   Printable  characters  (which
           must  be  positive,  less  than  256)  are checked according to the
           program's locale settings.

       <STRONG>o</STRONG>   The input is the KEY_MOUSE special key  associated  with  an  mouse
           event.

       The menu driver requests are as follows:

       REQ_LEFT_ITEM
            Move left to an item.

       REQ_RIGHT_ITEM
            Move right to an item.

       REQ_UP_ITEM
            Move up to an item.

       REQ_DOWN_ITEM
            Move down to an item.

       REQ_SCR_ULINE
            Scroll up a line.

       REQ_SCR_DLINE
            Scroll down a line.

       REQ_SCR_DPAGE
            Scroll down a page.

       REQ_SCR_UPAGE
            Scroll up a page.

       REQ_FIRST_ITEM
            Move to the first item.

       REQ_LAST_ITEM
            Move to the last item.

       REQ_NEXT_ITEM
            Move to the next item.

       REQ_PREV_ITEM
            Move to the previous item.

       REQ_TOGGLE_ITEM
            Select/deselect an item.

       REQ_CLEAR_PATTERN
            Clear the menu pattern buffer.

       REQ_BACK_PATTERN
            Delete the previous character from the pattern buffer.

       REQ_NEXT_MATCH
            Move to the next item matching the pattern match.

       REQ_PREV_MATCH
            Move to the previous item matching the pattern match.

       If the second argument is a printable character, the code appends it to
       the pattern buffer and attempts to move to the next item  matching  the
       new pattern.  If there is no such match, <STRONG>menu_driver</STRONG> returns <STRONG>E_NO_MATCH</STRONG>
       and deletes the appended character from the buffer.

       If the second argument is one of the above  pre-defined  requests,  the
       corresponding action is performed.


</PRE><H3><a name="h3-Mouse-Handling">Mouse Handling</a></H3><PRE>
       If  the  second  argument  is the KEY_MOUSE special key, the associated
       mouse event is translated into one of the above  pre-defined  requests.
       Currently only clicks in the user window (e.g., inside the menu display
       area or the decoration window) are handled.

       If you click above the display region of the menu:

       <STRONG>o</STRONG>   a REQ_SCR_ULINE is generated for a single click,

       <STRONG>o</STRONG>   a REQ_SCR_UPAGE is generated for a double-click and

       <STRONG>o</STRONG>   a REQ_FIRST_ITEM is generated for a triple-click.

       If you click below the display region of the menu:

       <STRONG>o</STRONG>   a REQ_SCR_DLINE is generated for a single click,

       <STRONG>o</STRONG>   a REQ_SCR_DPAGE is generated for a double-click and

       <STRONG>o</STRONG>   a REQ_LAST_ITEM is generated for a triple-click.

       If you click at an item inside the display area of the menu:

       <STRONG>o</STRONG>   the menu cursor is positioned to that item.

       <STRONG>o</STRONG>   If you double-click an item  a  REQ_TOGGLE_ITEM  is  generated  and
           <STRONG>E_UNKNOWN_COMMAND</STRONG>  is  returned.   This  return  value makes sense,
           because a double click usually means that an  item-specific  action
           should be returned.  It is exactly the purpose of this return value
           to signal that an application specific command should be executed.

       <STRONG>o</STRONG>   If a translation into a request was done, <STRONG>menu_driver</STRONG>  returns  the
           result of this request.

       If  you clicked outside the user window or the mouse event could not be
       translated into a menu request an <STRONG>E_REQUEST_DENIED</STRONG> is returned.


</PRE><H3><a name="h3-Application-defined-Commands">Application-defined Commands</a></H3><PRE>
       If the second argument is neither printable nor one of the  above  pre-
       defined  menu  requests  or  KEY_MOUSE,  the  drive  assumes  it  is an
       application-specific    command    and    returns    <STRONG>E_UNKNOWN_COMMAND</STRONG>.
       Application-defined commands should be defined relative to <STRONG>MAX_COMMAND</STRONG>,
       the maximum value of these pre-defined requests.


</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
       <STRONG>menu_driver</STRONG> return one of the following error codes:

       <STRONG>E_OK</STRONG> The routine succeeded.

       <STRONG>E_SYSTEM_ERROR</STRONG>
            System error occurred (see <STRONG>errno(3)</STRONG>).

       <STRONG>E_BAD_ARGUMENT</STRONG>
            Routine detected an incorrect or out-of-range argument.

       <STRONG>E_BAD_STATE</STRONG>
            Routine was called from an initialization or termination function.

       <STRONG>E_NOT_POSTED</STRONG>
            The menu has not been posted.

       <STRONG>E_UNKNOWN_COMMAND</STRONG>
            The menu driver code saw an unknown request code.

       <STRONG>E_NO_MATCH</STRONG>
            Character failed to match.

       <STRONG>E_REQUEST_DENIED</STRONG>
            The menu driver could not process the request.


</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
       These routines emulate the  System  V  menu  library.   They  were  not
       supported  on  Version 7 or BSD versions.  The support for mouse events
       is <EM>ncurses</EM> specific.


</PRE><H2><a name="h2-AUTHORS">AUTHORS</a></H2><PRE>
       Juergen Pfeifer.  Manual pages and adaptation for new curses by Eric S.
       Raymond.


</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
       <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_getch.3x.html">getch(3x)</A></STRONG>, <STRONG><A HREF="menu.3x.html">menu(3x)</A></STRONG>



ncurses 6.5                       2024-03-16                   <STRONG><A HREF="menu_driver.3x.html">menu_driver(3x)</A></STRONG>
</PRE>
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<ul>
<li><a href="#h2-NAME">NAME</a></li>
<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
<ul>
<li><a href="#h3-Mouse-Handling">Mouse Handling</a></li>
<li><a href="#h3-Application-defined-Commands">Application-defined Commands</a></li>
</ul>
</li>
<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
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